Typically, athletic footwear has been worn with conventional cotton shoe laces tied in a bow knot to hold the shoes to a person's feet. Loosening of the knot while walking or engaging in athletic activity inevitably occurs, resulting in the shoe not fitting as snugly as desired, or worse, the knot becoming completely undone, leaving the lace ends to flap about, possibly causing a misstep, stumble or fall.
Elastic laces have also been used on athletic shoes. Such laces are known to hold the shoe tightly and firmly to the foot, yet provide necessary yielding to slight variations in tension that accompanies walking or other athletic activity. See, for example, Larsen, U.S. Pat. No. 2,036,482 and Ivanhoe, U.S. Pat. No. 4,423,539. Elastic laces, however, suffer from the same disadvantages of cotton laces. They are also difficult to tie.
Devices presently exist for securing cotton shoe laces and preventing them from inadvertently becoming undone. See, for example, the following patents:
Boden, U.S. Pat. Nos. 3,845,875 and 4,102,019, describes a locking assembly comprised of a body member having a central passage through which the laces pass and a shiftable locking slide member for inserting into the passage to clamp the laces.
Yang, U.S. Pat. No. 4,393,550, describes a fastening member that utilizes a spring to hold the laces.
Mathes, U.S. Pat. No. 3,138,839, describes a device having a base and a cap wherein the laces are inserted through a hole in the base and pass out of the cap through two spaced holes. A knurled or roughened ball in the base prevents the laces from loosening.
Sales, U.S. Pat. No. 4,112,551, describes a cup element and a plug element which lock the laces between them.
The above locking devices have a number of disadvantages. Some require assembly by the user and/or time-consuming threading procedures. Others have moveable parts that wear out. Additionally, if it is desired to undo the laces, some of the devices require disassembling and, in the case of the Boden device, may require cutting the laces to remove the device. The above devices are even less effective with elastic laces due to the thickness and resiliency of elastic laces.